LVM Mirroring - Redhat

[Juan John]

server has SAN attached and dual mulpathing enabled and lvm's also configured.

Which command to know whether LVM mirroring is done on any lvm disks on the server ?

[Michal Kapalka (mikap)]

hi,

vgdisplay / lvdisplay

mikap

[Juan John]

Do it shows vg is mirrored ?
Can can we understand disk are mirrored

[Ivan Ferreira]

You can use the lvs command to verify the layout of the mirrored volume and the underlying devices for the mirror leg and the mirror log.

lvs -a -o +devices


Detailed info:

http://www.centos.org/docs/5/html/Cluster_Logical_Volume_Manager/mirrorrecover.html
http://kairo.wordpress.com/2009/05/06/making-lvm-mirror-on-linux-using-red-hat-cluster-suite-clvm-cluster-lvm-on-rhel-5/

[Juan John]

Do this shows mirroring. Seems no mirroring right ?

#lvs -a -o +devices

lvol1 vg01 -wi-ao 70.00G /dev/dm-7(0)
lvol1 vg01 -wi-ao 70.00G /dev/dm-6(5120)
lvol1 vg01 -wi-ao 70.00G /dev/dm-9(0)
lvol2 vg01 -wi-ao 70.00G /dev/dm-6(2560)
lvol2 vg01 -wi-ao 70.00G /dev/dm-7(5120)
lvol2 vg01 -wi-ao 70.00G /dev/dm-8(0)
lvol3 vg01 -wi-ao 70.00G /dev/dm-7(2560)
lvol3 vg01 -wi-ao 70.00G /dev/dm-6(7168)
lvol3 vg01 -wi-ao 70.00G /dev/dm-7(7168)
lvol3 vg01 -wi-ao 70.00G /dev/dm-8(4352)

[Ivan Ferreira]

First of all, as you can see, you dont have the "m" attribute. Is not mirrored.

http://www.tcpdump.com/kb/os/linux/lvm-attributes/intro.html

[Steven E. Protter]

Shalom,

Don't discount the fact that hardware mirroring would not be visible to your REHL system.

lvdisplay -v should show software mirror state if LVM was used to do the mirror.

SEP